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You are not logged in. Pages: 1 2 #1 20110601 19:55:54
Flaws in logic of solution to a couple of the logic problemsThe solution given for the problem of the white and black marbles is flawed. We are dealing with combinations here and not permutations. Once a white marble is drawn, it doesn't matter if it was the first or second marble. There are only two possible outcomes at this point and therefore the probability is one in two. #2 20110601 21:42:39
Re: Flaws in logic of solution to a couple of the logic problemsHi bobcatfans; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #3 20110614 18:58:15
Re: Flaws in logic of solution to a couple of the logic problemsI quite agree with your last member. The options are only that it is a white or a black marble, because whether or not you have already selected marble 1 or two from bag A the next outcome is a white anyway. #4 20110614 19:29:30
Re: Flaws in logic of solution to a couple of the logic problemsHi Anne Smith; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #5 20110614 22:32:19
Re: Flaws in logic of solution to a couple of the logic problemsAre you referring to this: Bags of Marbles  Solution ? "The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  Leon M. Lederman #6 20120725 21:57:17
Re: Flaws in logic of solution to a couple of the logic problemsI agree this answer is wrong it says the answer is 2/3 because you are picking marbles not bags. That answer is if you were picking bags. The probability of you picking a white marble is 3/6 or simplified 1/2. #7 20120725 22:17:23
Re: Flaws in logic of solution to a couple of the logic problemshi Nicholas, You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #8 20120725 23:03:30
Re: Flaws in logic of solution to a couple of the logic problemsThe problem is called Bertrand's box paradox. The limit operator is just an excuse for doing something you know you can't. “It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman “Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment #9 20120725 23:19:20
Re: Flaws in logic of solution to a couple of the logic problemsDoes the original problem state that the marbles are distinguishable or not? Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional). LaTex is like painting on many strips of paper and then stacking them to see what picture they make. #10 20120725 23:32:19
Re: Flaws in logic of solution to a couple of the logic problemsI think the probability stays the same in both cases. Did you look at the Wikipeadia article on the Bertrand's box paradox. The limit operator is just an excuse for doing something you know you can't. “It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman “Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment #11 20120726 04:25:33
Re: Flaws in logic of solution to a couple of the logic problemsYup! I looked at the Wiki article. But alas I haven't had time to really think about it all. I'm helping a friend move most of today. Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional). LaTex is like painting on many strips of paper and then stacking them to see what picture they make. #12 20131023 19:01:06
Re: Flaws in logic of solution to a couple of the logic problems
Bob thank you for the pointer. #13 20131023 19:20:01
Re: Flaws in logic of solution to a couple of the logic problemsActually scratch that I think I do see the flaw in the official answer. #14 20131023 19:28:31
Re: Flaws in logic of solution to a couple of the logic problemsThe problem is that door 2 might have a car behind it and not a goat. The limit operator is just an excuse for doing something you know you can't. “It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman “Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment #15 20131023 21:08:25
Re: Flaws in logic of solution to a couple of the logic problemshi ILIA You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #16 20131024 06:56:25
Re: Flaws in logic of solution to a couple of the logic problemsHi bob. #17 20131024 07:06:11
Re: Flaws in logic of solution to a couple of the logic problemsCorrection: I do see that I made the assumption about host's random choice when I argued that if he revealed a car ... #18 20131024 07:12:05
Re: Flaws in logic of solution to a couple of the logic problemsHi; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #19 20131024 07:55:40
Re: Flaws in logic of solution to a couple of the logic problems
I cannot blame him. It is very counterintuitive! The limit operator is just an excuse for doing something you know you can't. “It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman “Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment #20 20131024 14:36:01
Re: Flaws in logic of solution to a couple of the logic problemsI got it wrong too, proving that bobbym = Paul Erdos. That was all I needed to convince myself that I belonged in math. After all, if I could get the same wrong answer as him I must be great too? I began to search for other probability problems that I could get wrong and lo, I found them. In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #21 20131025 07:52:18
Re: Flaws in logic of solution to a couple of the logic problemshi ILIA You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #23 20131026 02:18:03
Re: Flaws in logic of solution to a couple of the logic problemsHi Nehushtan; 'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.' 'God exists because Mathematics is consistent, and the devil exists because we cannot prove it' 'Who are you to judge everything?' Alokananda #24 20131026 02:22:18
Re: Flaws in logic of solution to a couple of the logic problemsHi Agnishom. 134 books currently added on Goodreads #25 20131026 18:41:11
Re: Flaws in logic of solution to a couple of the logic problemsHi bobcatfans; 'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.' 'God exists because Mathematics is consistent, and the devil exists because we cannot prove it' 'Who are you to judge everything?' Alokananda Pages: 1 2 